2026-05-03T09:45:11Z https://ezb-oai.ur.de/zdb/oai2.php marc21 http://www.loc.gov/standards/marcxml/schema/MARC21slim.xsd http://www.loc.gov/MARC21/slim/ MARC21-xml http://www.loc.gov/standards/marcxml/schema/MARC21slim.xsd http://www.loc.gov/MARC21/slim/ oai_dc http://www.openarchives.org/OAI/2.0/oai_dc.xsd http://www.openarchives.org/OAI/2.0/oai_dc/